Circuit breaker



July '4, 1944. w. H. WOODS CIRCUIT BREAKER Filed Feb. 1, 1943 3 Sheets-Sheet 1 INVENTOR ZZiam b07601: ATTORNEY w. H. woobs CIRCUIT BREAKER July 4, 1944.

Filed Feb. 1, 1943 3 Sheets-Sheet 2 INVENTOR m h ools ATTORNEY July 4, 1944.

w. H. WOODS 2,352,928

CIRCUIT BREAKER Filed Feb. 1, 1943 3 Sheets-Sheet 3 INVENTOIR A TTORNE Y Patented July 4, 1944 CIRCUIT BREAKER William H. Woods, Garden City, Mich., assignor to Square D Company, Detroit, Mich, a corporation of Michigan Application February 1, 1943, Serial No. 474,315

8 Claims.

This invention relates to devices for making and breaking electrical circuits and more particularly to automatic electric circuit breakers.

The object of the present invention is to provide an improved form of double throw quick make and break automatic electric circuit breaker of simple and economical construction.

Other objects and features of this invention will be readily apparent to those skilled in the art from the specification'and appended drawings illustrating certain preferred embodiments in which:

Figure 1 is a sectional view taken on the line 1-1 of Figure 2 and showing a switching member in contacts engaged position.

Figure 2 is a front elevational view of the circult breaker, according to the present invention. with the cover and handle removed and with the trip lever shown in phantom to thereby illustrate in clearer detail the interior of the device.

Figure 3 is a sectional view taken on the line III-III 01 Figure 2 and showing a switching member in contacts disengaged position.

Figure 4 is a view similar to Figure 1 but showing the parts in contacts disengaged position.

Figure 5 is a view similar to Figure 1 but showing the parts in automatic tripped position.

Figure 6 is a sectional view omitting the opera-ting mechanism and showing the base assembly. 4 Figure 7 is a sectional end elevational view showing only certain of the details.

The circuit breaker according to the present invention embodies a generally cup-shaped insulating enclosing member I having a metallic cover 2 sealably secured thereto by stud 2 and with an insulating sheet 4 disposed back of the cover 2. A pair of locking bushings i are carried by the cover 2 and extend downwardly into recesses 6 provided in side walls I and I of the enclosing member i and are adapted to receive mounting studs, not shown, to secure the circuit breaker at a desired location.

Each of the opposite side walls land I of the enclosing member I are slotted as at 9 to receive portions ll of a pair of generally S-shaped conducting connectors l2 and it; which connectors are adapted to extend through openings i4 and is provided in base ll of the enclosing member I to the exterior. The slots 8 are so located within walls 1 and 8 that the connectors I2 and I; when fltted therein are positioned within the enclosing member diagonally across from one another. Studs I1 and their cooperating nuts is secure the connector I2 and II to walls 1 and B. At the exteriorly disposed ends is of each of the connectors i2 and I3, terminal studs 2i are carried for securing cable leads to the circuit breaker; and, upon the interior ends 22 and 23 of the connectors, stationary contact surfaces 24 and 25 are mounted.

A connector or conducting member 26 having a U-shaped central portion 21 and arms 28 and 29 extending from and at right angles to legs 3| and 22 thereof is disposed within the enclosing member I and lies upon ledge portions 33 provided on the base of member I, and is secured in place by studs 35. The ends of arms 28 and 29 are upturned as at 38 and 21, and to these upturned portions are welded the bimetallic members 38 and 39. The U-shaped central portion 21 of the connector 28 provides a common terminal and carries a terminal stud 4|. A member 42 comprised of insulating material is disposed over the conducting member 26 and covers a substantial portion of the bottom of the base. Studs 43 threaded into arms 28 and 29 'of connector member 28 hold the insulating member 42 in position.

A metallic supporting or mounting member 44 is provided within the enclosing member I and comprises a pair of opposed legs and 46, which legs are closely fltted into slots 41 provided in walls 4| and 48 of the enclosing member I. Mounting flanges 40 are bent from legs 45 and 48 and rest upon the insulating member 42. Stud H threaded into the flanges 40 secure them to the insulating member 42 to thereby retain the supporting member 44 within the enclosing member I. A pair of pins l2 and 52 are carried by legs 48 and 48, one above the other. A manual operator I4 is provided at the top of the breaker and includes a body portion ll of molded insulation and a handle portion N which extends through openings in the supporting member 44, the insulating sheet 4 and the cover 2 to the exterior. The body portion 55 carries a pair of generally U-shaped members 51 and 58, the legs of which are used for a purpose to be hereinafter described. The pin 52 passes through openings in the legs of members 51 and I! tothereby provide a pivotal mounting for the manual operator N. The manual operator 54. through members El and El, operates a pair of actuating systems, to be further described, to effect movement of a pair of contact members 58 and I to control electric circuits. Each of the contact or switch members 58 and BI and the actuating means for eilecting movement thereof are identical and, therefore,

but one of these switching assemblies, and that.

the one including contact member 58, will be described in detail.

Contact member a includes and 82 through which pin 53 is passed to pivotally mount the contact member. A contact surface 84 is provided at one end of the contact member 59 for cooperation with stationary contact 24 to complete a circuit therethrough. A flexible lead interconnects the bimetallic member 38 a pair of legs 82 and the contact member l! to place the bimetai lic member in series circuit with the contacts. A portion of the flexible lead I lies within recess I so that the lead does not interfere with the operation of the actuating parts. A generally U-shaped member N is disposed upon pin is and between legs 6! and II of contact member II. Legs i1 and 8| of the U-shaped member I! carry pin ss which pivotaliy mounts one end of a spring guide II. The switch member I supports a cross piece If between its legs I! and I, which cross piece is provided with a slot therethrough to receive the free end of the guide II. A compression spring ll is disposed about guide II and is interposed between shoulder formations ontheguideandthecrosspiece 12 iorapurpose tobedescrlbed. Leg" ofmemberslhasan end thereof bent outwardly to eflect a flange portion ll and has portions bent inwardly from its lateral edges to provide the flanges II and II.

I'lange'llextendsintoanopeninglliniegll of the supporting member Is and engages the defining edges thereof to limit the extent of movement of the member I. To provide for the actuation of member ll, leg ll of member I! carried by the manual operator '4 is extended into the space between flanges II and I. on member 00 and is ensageable with one or the other, dependent on the direction of movement of the manual operator, and movement of the engaged flange by leg II will effect pivotal movement oi the member it.

A trip member I! comprising a pair'of legs II and s2 and a latching tip I8 is pivotally mounted on pin II, the pin passing through openings in the legs II and .2. A spring is has one end secured to the leg 02 of the trip member II and the other end fastened to an extended arm as provided by the support N, and exerts its bias on the trip member II to continually bias it for movement in one direction. The latching tip st of trip member I. engages the free end of the bimetallic element 8| and normally maintains the trip member in engaged position against the bias of spring as. A flange II is provided on leg I! of the trip member and is adapted to engage leg or member II when the trip member is released by the bimetal II on current overload to effect movement of the member CI to bring about automatic separation of the contacts will be further described.

'lhe second leg 81 of member 1 serves as a resetting member for positively returning the trip member ll into engagement with the bimetal ll after having been released on current overload.

A flange II is bent from leg ll of the supporting member u and extends into the path of movement of the contact member is to provide a stop therefor to limit the extent of movement thereof, in clockwise direction, to contacts open position.

The actuating means for contact member oi, as was stated above, is similar to that for contact member 89 and embodies the arm 09 on member ss which extends between flanges Ii and 2 carried by arm 83 of a, pivotal member ill similar to member SI, and is actuable to move member 04 to effect a change of direction of the line of force of overcenter spring 95 operative on contact member ii to effect snap movement of this contact member. A trip member N is associated with this switching unit and is released by bimetal I! on current overload, and

through flange 91 provided thereon engages and moves arm II on member as to move this member for actuation of the overcenter spring ll to effect automatic movement 0! the contact member II. A resetting arm I! is provided on member is for returning trip member as into enga.g.ement with its associated bimetallic member The operation of the circuit breaker will now be described:

Movement of the manual operator is effects movements of the contact members is and Ii to their "on" and "of!" positions. However, but one of the contact members is adapted to be in contacts engaged position at one time although both may simultaneously be in the contacts disengaged or "01!" position, this latter condition being effected when the manual operator l4 occupies its center position. Figure 1 shows contact member II in the "on" position. eflected by moving the handle as from its center position to the left hand position shown. When contact member II is in "on" position. contact member ll will occupy its ofl"' position, as is seen in Figure 8. Upon clockwise movement of the handle I! from its left hand position to the center position of Figure 4, arm ll, carried by the manual operator, will transmit force to flange II to rotate member as to move pin II to compress spring II and move one end thereof until the line of force of this spring is carried through pivot is of the contact member ll whereupon the energy in the spring becomes active to move the contact member Bl with a snap, in a clockwise direction, to disengage the contacts. The contact member I. will rotate until it engages the limiting stop II as shown in Figure 4; and member I will be moved by the released spring force until flange It strikes the edge of slot 11. This movement of the manual operator is from its left hand position to the center position has no effect on contact member ii and it remains in "oil" position. Arm ll of member I. will, however, be moved, on this movement of the operator I, from the position shown in Figure 8 to a position adjacent flange Ii. Movement of the handle I! clockwise from its center position to its right hand position will cause arm is to apply force to flange Ii to rotate member N and effect a compression of spring I until the line of force of this spring is carried through pivot ll of the contact member I to thereby move the contact member Ii 'th a snap to contacts "on" position.

This movement of the handle II from its center position to the right to effect actuation of the contact member Ii to "on" position has no effect on contact member I! and it remains in the "off" position of Figure 4. Arm ll, however, will be carried by the manual operator away from its associated flanses II and fl and to a position relative thereto similar to the position that armllinl 'iguresbearstoitsassociatedflanges DI and I2.

Return movement of handle ll counter-clockwise, from its right hand position to its center position will cause arm II to apply force to flange I! to effect a reverse action of contact member ii to contacts "off" position. This movement will carry arm II to a position adjacent flange I! so that a continued counter-clockwise movement of handle 88 from center position to the left hand position of Figure 1 will cause a pivotal movement of the actuating member 68 and efi'ect snap movement of the contact member 58 into contacts "on" position (Figure 1) while maintaining contact member II in its position.

Thus, each side oi the breaker controls a circuit without interference from the switching system on the opposite side. Movement of the handle I! from the left hand position 01' Figure l to the center position of Figure 4 and back to the left hand position will eflect a cycle of movement of the contact member 59 only, while contact member BI is maintainedin its"oi!" position. Movement of the handle from center position to right hand position and return to center position will effect movement of contact member II from "oiI to "on" and back to 011" and contact member 59 will remain in 011" position during these movements.

Thus, in the center position of handle ll both the contact members I! and ll will be in "0! position; and movement oi the handle II from center position to the left or to the right will eflect movement of but one of the contact mem-,

bers, to the left it is contact member II that is actuated: and to the right, movement or contact member ll is eflected.

In the automatic operation of the parts, as-

suming the circuit through contacts 24 and s4 to be closed as in Figure l, the occurrence of an overload current heats the bimetallic element II to bend it clockwise to move it out oi engagement with tip 83 oi the trip member II, whereupon the trip member 10 will move clockwise under the bias of spring 84 and flange I. thereon engages and positively movesleg ll of member "to move the line of force of spring I! through the pivot 01 contact member II to elect a snap movement of the contact member to contacts "on" position; at the same'time flange 10 on member 88 engages and positively moves arm II to thereby carry the manual operator '4 to its center position. To reset the trip member 1., the manual operator N is moved counter-clockwise from its center position to the position of Figure 1 and the depending arm I! engages and positively returns the trip member I! to a position where the latching tip 83 will re-engage bimetal 8|, if the bimetal has cooled sumciently to return to its initial position. This resetting movement oi the manual operator also simultaneously effects a snap movement or the contact member ll into "on" position for arm 18 will move member II to effect a change in the direction oi the line of force 01' spring II from one side to the other of the pivot oi contact member It. If the condition of overload still exists and the manual operator I4 is released, the parts will promptly move to contacts oi! position for the bimetal II will act to release trip-member 19.

I1 the circuit should be through the second set of contacts 25, I4 and an overload current were impressed thereon trip member it would be released by bimetal 38 to effect a snap movement of contact member ll to oilf' position, and handle I. will move from its right hand position to the center position.

While certain preferred embodiments of the invention have been specifically disclosed, it is understood that the invention is not limited thereto, as many variations will be readily apparent to those skilled in the art and the invention is to be given its broadest possible interpretation within the terms of the following claims. I

What is claimed is:

i. In a double throw automatic electric circuit breaker, a pair of stationary contacts, a pair oi movable contacts, a pair 01' switch members for position, means associated tacts disengaged position, and

moving said movable contacts into and out oi engagement with said stationary contacts. snap acting means operatively connected to each 0! said switch members for eflecting a quick movement of each into and out of contacts engaged with said switch members whereby but one oi said switch members is adapted to be in contacts engaged position at a time, a manual member for actuating said snap acting means, saidmanual member being operative to alternately move said switch members into contacts engaged position, and current responsive means operative on each of said switch members to etlect automatic movement thereof to contacts disengaged position on the occurrence oi a current overload.

2. In a double throw automatic electric circult breaker, a pair or pivotal switch members, movable contacts carried thereby, stationary contacts adapted to be engaged by said movable contacts, snap acting means operatively associated with each of said switch members, manual means actuable on said snap actingmeans and adapted to occupy a plurality of positions oi rest, said manual means when moved in either direction from a central position or rest operating to eii'ect snap movement of one of said switch members to contacts engaged position, while maintaining the other of said switch members in concurrent responsive means actuable on the occurrence 0! a current overload to eil'ect automatic movement 01' a switch member from contacts engaged to contacts disengaged position.

In an automatic electric circuit breaker, a stationary contact, a movable contact, a switch member movable to move said movable contact to engage and disengage with said stationary contact, a pivotal member, overcenter spring means interconnecting said switch member and said pivotal member, a provided on said pivotal member and spaced from each other, a manual member, means carried by said manual member and extending between said flange portions, said means on oscillation of said manual member to and from a given position 0! rest acting alternately on said flange portions to move said pivotal member in opposite directions to actuate said overcenter spring means and eii'ect snap movement of said switch memher to and from contacts engaged position, and

current responsive means operative, on the occurrence of an overload current, to move said pivotal member to effect snap movement oi said switch member to contacts disengaged position.

4. In an automatic electric circuit breaker, a stationary contact, a movable contact, aswitch member movable to eilect movement of said movable contact for engagement with said stationary contact, a pivotal member provided with a pair of leg portions, overcenter spring. means interconnecting said switch member and said pivotal member, spaced means carried by one 0! said leg portions, a'manual member, a member carried by said manual member and extending be tween said spaced means, said member on movement of said manual member being adapted to alternately apply force to said spaced means to eilfect movement of said pivotal member in alternate directions to actuate said overcenter spring means and effect snap movements of said switch member to and from contacts engaged position, and a pivotal trip member movable on the occurrence of an overload current to engage the other leg portion of said pivotal member to move said pair of flange portions pivotal member to effect snap movement of said switch member to contacts disengaged position.

5. In an automatic electric circuit breakena stationary contact, a movable contact, a pivotal switch member movable to move said movable contact for amusement and disengagement with said stationary contact to make and break an electrical circuit therethrough. a pivotal element provided with a pair of leg members, overcenter spring means interconnecting said switch member and said pivotal element, spaced flange portions provided on one of said leg members, a manual operator, an arm carried by said manual operator and extending between said spaced flanges, said arm on movement of said manual operator being adapted to alternately apply force to said spaced flanges to effect movement of said pivotal element in alternate directions to actuate said overcenter spring means and effect snap movements of said pivotal switch member to and from contacts engagedposition, a pivotal trip member, spring means continually biasing said trip member for movement in one direction. and a bimetallic element restraining said trip member from movement, said bimetallic element releasing said trip member for movement on the occurrence of a current overload.

6. In an automatic electric circuit breaker, a stationary contact, a movable contact, a switch member, a pivot therefor, said switch 'member being movable to move said movable contact for cooperation with said stationary contact to make and break an electrical circuit, a pivotal element mounted on said pivot and comprising a pair of leg members, snap acting means interconnecting said switch member and said pivotal element, spaced flange portions provided on one of said leg members. a manual operator; a second pivot and on which said manual operator is mounted, a member supported by said manual operator and extending therefrom into the space between said flange portions, said member upon movement of said manual operator transmitting force to said flange portions alternately to effect movement of said pivotal element in opposite directions to actuate said snap acting means to effect quick pivotal movements of said switch member to and from contacts engaged position, a trip member also pivotally mounted on said second pivot, spring means continually exerting its bias on said trip member for movement thereof in one direction, a bimetallic element engaging said trip member to hold it restrainedagainst the bias of said spring means, said bimetallic element-releasing said trip member for movement on the occurrence of a current overload to engage and move said pivotal element to efiect snap movement of said switch member to contacts disengaged position, and a second member supported by said manual operator and adapted to be moved thereby into engagement with said trip member to move said trip member to re-engage said bimetaliic member after its release therefrom on current overload.

7. In a double throw automatic electric circuit breaker, an insulating base, a pair of stationary contacts disposed therein, a mounting member carried by said base, a pair of switch members pivotaliy supported on said mounting member, a movable contact carried by each of said switch members for cooperation with said stationary contacts, a pair of pivotal members supported on said mounting member, snap imparting means interconnecting said switch members and said a,ass,oss

pivotal members, each of said pivotal members being provided with spaced i'iange portions, a manual operator for moving said switch members and having a plurality of positions of rest, said manual operator when in its central position of rest maintaining both of said switch members in contacts disengaged position, a pair of members rigidly supported by said manual operator and extending therefrom into the spaces between said flange portions, movement of said manual operator in a first direction from said central position of rest to a second position of rest causing the first of said extending members to apply force to one of said flange portions on one of said pivotal members for movement thereof to actuate a snap imparting means associated therewith to effect snap movement of the first of said switch members to contacts engaged position, return movement of said manual operator to said central position of rest causing said extending member vto apply force to the other of said spaced flange portions to move said pivotal member to effect snap movement of said first switch member to contacts disengaged position, movement of said manual operator from said central position of rest in a second direction to a third position of rest causing the second extending member to apply force to a flange portion on said second pivotal member for movement thereof to actuate a snap imparting means associated therewith to effect snap movement of'said second switch member to contacts engaged position, return movement of said manual operator to said central position causing said second extending member to apply force to the other of said spaced flange portions to move said second pivotal member to effect snap movement of said second switch member to contacts disengaged position, and current responsive means operative on current overload to actuate the switch member in contacts engaged position to effect movement thereof to contacts disengaged position.

8. In a double throw automatic electric circuit breaker, a generally cup-shaped insulating base, a pair of stationary contacts disposed therein, a pair of switch members oppositely directed to one another and supporting movable contacts for cooperation with said stationary contacts, a pair of pivotal members, overcenter spring means interconnecting said pivotal members and said switch members, a manual member, means carried thereby and adapted to engage and move said pivotal members alternately to effect snap movements of one of said switch members to and from contacts engaged position while maintaining the other switch member in contacts disengaged position, a connector member disposed adjacent the bottom of said insulating base and extending diagonally thereacross, a pair of bimetallic members secured to said connector, one at each end, flexible leads interconnecting said himetallic members and said switch members, trip members provided for each switch member, each trip member being spring biased for movement in one direction, said bimetallic members engaging said trip members to restrain them against said spring bias, said bimetallic members being adapted to flex to release said trip members on the occurrence of an overload current, each trip member when released being movable to engage and move a pivotal member to effect snap movement 01! a switch member to contacts disengaged po- 5 tion.

WILLIAM H. WOODS. 

